communication system

One of the earliest practical applications of automation was in telephone switching. The first switching machines, invented near the end of the 19th century, were simple mechanical switches that were remotely controlled by the telephone user pushing buttons or turning a dial on the…

Communications systems are of growing significance and complexity in commercial, institutional, and industrial buildings. Thus communications wires for telephones, public-address systems, and computer data are free to take many paths through the building, including vertical risers, ceiling sandwich spaces, and wireways in floor slabs similar…

The modern communications industry is among the most spectacular products of electricity. Telegraph systems using wires and simple electrochemical or electromechanical receivers proliferated in western Europe and the United States during the 1840s. An operable cable was installed under the English Channel in 1865, and a pair…

…World War II, advances in communication technology made pigeons increasingly obsolete. In December 1956 the U.S. Army made it official: Pigeon service would end.

…by the speeding up of communication, which allowed news to be gathered instantly from distant cities via the telephone or even from foreign countries through the seabed cables laid between Dover, England, and Calais, France, in 1851 and across the Atlantic in 1866. In 1815, when the mounted courier and…

The vehicles discussed above would be nothing more than efficient conveyances if police officers were unable to communicate instantly with each other and the public. In the earliest police forces, communication was accomplished through oral or written orders in an administrative chain of command.…

Railroads were among the first to adopt the electric telegraph and the telephone, both for dispatching trains and for handling other business messages. Today, the railroads are among the larger operators of electronic communications systems.

…how to handle noise in communication systems. Noise is an inescapable feature of the universe. Much of the noise that occurs in communication systems is a random noise, often called thermal noise, generated by heat in electrical circuits. While thermal noise can be reduced, it can never be completely eliminated.…

communications process by which measurements are made and other data collected at remote or inaccessible points and transmitted to receiving equipment for monitoring, display, and recording. Originally, the information was sent over wires, but modern telemetry more commonly uses radio transmission. Basically, the process is…

Rapid and continuous advances in communications and computer technology are spurring a host of new concepts in road traffic control. Automobiles equipped with on-board computers, driver displays, and communications devices will receive instructions about the optimal path to a destination from a traffic control centre. The vehicle also will periodically…